Electric motor and electric power steering apparatus equipped with the motor

Abstract

An electric motor driven by three-phase electric power includes armature windings that are connected in series, via an armature-winding connecting line, for each of a plurality of groups of three or N circumferentially-adjoining poles to thereby provide three-phase armature windings, wherein N is an arbitrary number equal to a multiple of three. The armature-winding connecting line connects in series the adjoining armature windings in such a way as to not substantially straddle a relatively great part of the outer periphery of any of the adjoining armature windings.

Description

FIELD OF THE INVENTION [0001] The present invention relates to electric motors and electric power steering apparatus equipped with such electric motors. BACKGROUND OF THE INVENTION [0002] As well known, the electric power steering apparatus are steering assisting apparatus which are constructed to activate an electric motor (steering assisting motor) as a human driver manually operates a steering wheel of a motor vehicle, to thereby assist the driver's manual steering effort. In such electric power steering apparatus, the steering assisting motor, which provides steering assist force or torque, is controlled on the basis of a steering torque signal generated by a steering torque detection section detecting steering torque that is produced on the steering shaft by driver's operation of the steering wheel and a vehicle velocity signal generated by a vehicle velocity detection section detecting a traveling velocity of the vehicle, so as to reduce manual steering force to be applied by ...

AI Technical Summary

Benefits of technology

[0009] Namely, in the motor of the present invention, the armature-winding connecting line, connecting in series the adjoining armature windings, is led in such a way as to not arcuately extend around (or substantially straddle) a part of any of the adjoining armature windings. Therefore, the armature-winding connecting line can be reduced in length and hence can have reduced electrical resistance, which should contribute to enhancement in the torque output performance of the motor.

[0012] With the motor capable of achieving enhanced torque output performance, the electric power steering apparatus of the invention can impart more appropriate steering assist force and can significantly improve the steering feel.

Problems solved by technology

Further, the neutral-point connecting line 120 is led or positioned on the same side as the armature-winding connecting lines 110, so that layout or placement of the electric motor tends to be difficult and human operators tend to confuse the armature-winding connecting lines 110 and neutral-point connecting line 120 during assembly operations.

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